Torque transmission



March 13, 1945. A. Y. DODGE 2,371,228

TORQUE TRANSMISSION Filed Feb. 17, 1943 2 Sheets-Sheet 1 March 13, 1945.

A. Y. DODGE TORQUE TRANSMISSION Filed Feb. 17, 1943 2 Sheets-Sheet 2 Patented Mar. 13, 1945 UNITED STATES PATENT OFFICE TORQUE TRANSMISSION Adiel Y. DodgaRockIord, Ill.

Application February 11, 1943) Serial Nemesis. (on. 74-29:)

12 Claims.

Th s invention relates to torque transmissions and more particularly to. devices for transmitting torque at a plurality of selected speed and torque ratios.

One of the objects of the invention is to provide a torque transmission including a differential gear unit which is so constructed and arranged as to function either as a reduction gear or as a clutch. In this construction, one element of the gear unit is held against reverse rotation to provide a fulcrum for torque multiplication and the gears are enclosed to form a fluid pump so that when flow of fluid through the gears is obstructed they will lock to transmit torque at a unitary ratio.

Another object of the invention is to provide torque transmission including a gear type fluid pump unit in which outlet pressure from the unit is imposed on its housing parts to force them into sealing engagement with the gears.

Still another object of the invention is to provide a torque transmission in which torque changes are produced hydraulically under the. control of a simple unitary valve construction. According to "one feature of the invention, the valve is formed by an elongated tube having ports communicating with the hydraulic units and which may eflectively control a plurality of such units.

Still another object of the invention is to provide a torque transmission in which a plurality of torque ratios may be obtained through the use of one or more combined gear reduction and clutch units.

The above and other objects and advantages of the invention will be more readily apparent from the following description when-read in connection with the accompanying drawings, in

which- Figure 1 .is a longitudinal section with parts in elevation of a transmission embodying the invention; and

Figure 2 is a partial section on the line 22 of Figure l.

The transmission illustrated is adapted to connect a driving shaft II] which may be the crank shaft of an engine to a driven shaft H which may be connected to the driving wheels of a vehicle or to any other load to be driven. The driving shaft is connected to the drivin member of a unit. I2 which may be a conventional friction clutch, a fluid fly wheel, a hydraulic torque converter or a fluid displacement clutch of the type more particularly described and claimed in my on November 26, 1941. In any event, the unit I! is of a type adapted to transmit torque under some conditions and to interrupt torque flow under other conditions. In the case of a fluid fly wheel or torque converter, it will be noted that torque fiowis interrupted at low speeds when the velocity of fluid in the unit is insuflicient to drive its driven member.

The driven member or the unit I2 is connected through a shaft l3 to a casing 14 forming the outer casing of a planetary differential gear set. The casing It comprises two side plates to which a ring I5 is connected in fluid tight relation, the ring having formed thereon internal gear teeth It so that it forms a ring gear for the gear set. The ring gear meshes with a series of'planet pinions l'l supported, on hollow spindles or arbors l8 extending between and through side plates !9 which form a planet carrier. The planet pinion H in turn meshes with a sun gear 2| to complete the differential gear set.

The side plates l9 forming the planet carrier ure 2, the inlet passages 21 communicate with the ends of the gear teethrto supply fluid thereto,

each passage opening into the gear teeth at one point 28 where the planet pinions mesh with the sun gear and at another point 29 where the planet pinions mesh with the ring gear. The side plates are further formed with exhaust ports 3| communicating with the ends of the gear teeth at points across the intermeshing teeth from the points 28 and 29 through which fluid may be forced by the pump into the casing I4.

In order that the gear set may act as a reduction unit, the sleeve 26 connected to the sun gear is connected to a one-way brake 32 acting between the sleeve and a fixed housing part 33 to prevent rearward rotation of the'sun gear. With this construction, when the ring gear is driven and thesun gear is held againstreverse rotation, the planet cage will be turned forwardly at reduced speed and increased torque.

In operation of the gear set, when fluid-is being pumped from the inlet into the'casing 14 the fluid in the casing will act against the side-plates I9 substantially their entire area to urge them toward the ends of the gears. Since the area on copending application, Serial No. 420,479, flied the inside of h plates exposed to the correspondvwith a port 49 adap ed to te t t (115- different ratio will be provided in th ing high pressure is relatively small, the plates ny ne of a plur y of control positions indiwill be forced into sealing engagement with the cated by the dotted lines extending from the conear teeth with a force proportional to the distrol shaft and numbered respectively I, 2, 3 and charge pressure to assist in maintaining a seal 4. The sleeve 48 is formed to flt closely into the between the gears and the side plates. The pres- 5 shaft 22 around the ports to control them but sure on opposite sides of the gear set is equalized may fit loosely in the remainder of the shaft and through the hollow arbors l8 which further enthe extension 45. able the unit to function with only one discharge With the parts in shifted position I, as shown, passage on one side of the gear set. In order the discharge passage 23 is closed by the valve that the gear set may function as a pump as de- 10 sleeve and the inlet passage 24 registers with the scribed, the spaces between the gears are closed port 52. At the same time, the discharge passage by blocks 34 as shown in Figure 2 which fit closely 41 is closed and the inlet passage 43 communiagainst the ends of the gear teeth. cates with the port 56. Thus in this position of In o der to limit t p e in t casing N the valve, the inlets of both diir rential gear units as a safety measure and t absorb shock loads 50 are open and the outlets of both units are closed. that a sm th r operating smissi n is p Thus the units will be filled with liquid and since Videdpressure relief valve is connected to their outlets are closed they will be locked to form the casing. The valv 0 is preferably adjusted in effect fluid clutches. In this position, when to p at a Pressure e hat greater than that the unit I2 is in driving condition, torque will be d v l p d at normal full torque operation o i go transmitted from the driving shaft to the driven will remain closed during normal operation. shaft t n -t w r t Howeve when t e al as hereinafter de- When the collar 51 is shifted to position 2, the c ed. is moved to close the exhaust P t 23 a inlet port 24 of the first gear unit will be closed p e su h r th n mal l be dev lop d n by the valve sleeve and its outlet ort 23 will be he casing l4 due to inertia efiects and this pr sas open throughout port 49. The inlet port 43 of sure will be relieved by the v lv Thlls t the second unit will still be open through the d w l be P d p smoothly without shock valve port 55 and its outlet port 41 will be closed he a ve 2 so serves as safety device to limit by the valve sleeve. In this position, no fluid will the fluid pressure in the casing l4 a t limit e be supplied to the first gear unit and any fluid t que w h can be trensmlttedso therein will be freely discharged through its out- A s c d planetary ge r unit similar to e first let so that the several elements of this unit may n just described is provided in th si turn freely relative to each other. As the ring on a d compr e a easing formed b i gear I6 is driven forward, it reacts through the p ates ca r n a r ng ear 6- he casin s h planet pinion l1 and tends to turn the sun gear a a ns v s tati by a on -way rake 36' 30 2| backward. Since this is prevented by the oneaoting between n extension th f d a fixed way brake 32, the planet carrier will be turned u g p e g m 5 meshes with a forward and will drive the sun gear 4| of the secseries f Planet pinions 31 carried by sid plates 0nd unit at reduced speed and increased torque. 33 fo g a r Carrier d between which the The second unit still functions as a closed clutch p s ar upp rt d on hollow ar rs r spin- 0 and transmits torque received from the first unit dies 39. he planet Pinions in turn, mesh to the driven shaft at a unitary ratio so that the w th a sun e r 4| which is connected to the driving shaft will drive the driven shaft at a speed hOllOW shaft 22. One Of the Side plates 38 1S and torque determined by the gear ratio of the formed with inlet passages 42 communicating. first it, with a port 43 in the shaft 22 and the side plates 45 When the collar 51 is shifted to position 3, the are further formed with discharge passages to inlet port 24 of the first unit will be open through conduct fluid through the side plates into the th a v port 5| space within housing 35. The carrier formed by nit will b close side Plates 33 is Connected to t driven shaft ll 0nd unit will be closed and the discharge port '41 by a t lar exte i n 45 keyed to the shaft and of this unit will be open through the valve port 54. closed by a plug 46. Thus, at this time the first unit operates as a The pace within the housing 35 communicates closed clutch to transmit torque at a unitary through a discharge po t 7 in t e tub ar shaft ratio to the sun gear 4| of the second unit. This 22 with the interior of the shaft, the discharge tends to turn the ring gear 36 backward which is port 41 being angularly displaced from the inlet prevented by the one-way brake 31 so that the port 43 to conserve space. planet carrier and the driven shaft will be turned The several discharge and inlet ports ar 0 forward at reduced speed and increased torque. trolled by a unitary valve formed by an e o g ted Since the sun gear of the second unit forms its tube or sleeve 48 slidable in the shaft 22 and in driving m mb r whereas the ring gear of the first the tubular extension I5. The sleeve is formed unit is its driving member, it will be noted that-a e two units so h e p rt 2 p r i d 2 adap d to r t that the intermediate positions 2 and a as above with the inlet port 24, ports 53 and 54 d p e to described, provide a different overall ratio bere ls r wi h he discharge p r 41, and p r 55 tween the driving and driven shafts.

and 56 adapted to register with the inlet Port 55 when the collar 51 is shifted to position 4, the The sleeve is controlled by a collar 51 connected outlet port 23 of the first unit will be open around to the sleeve by a pin 53 extend g through the end of the valve sleeve and the inlet port 24 gated slots in the tubular extension 45 and is supwill be closed. Outlet port 41 of the second unit plied with fluid from any sui le source, preferwill be open through valve port 53 and the inlet y under a l w pressure through a passa e 59 port 43 will be closed. In this condition, both communicating with a housing part 6| which engear sets act as mechanical reduction units in closes the rear end of the extension 45 and the series to provide a very high torque ratio between collar 57. The collar may be controlled by a yoke the driving and driven shafts. It will be undern t s o c ed 0 8 ol shaft 51 stood that if a torqueconverter is used at l2, the through which the collar may be moved through ratios provided by the gearing in the several and the discharge port 23 of this Q d. The inlet port 43 of the secaaraaee of reverse gear mounted in a housing 50 around.

the driven shaft H, which housing may also inclose a power take-ofi mechanism or other desired power transmitting devices.

While one embodiment of the invention has been shown and described in detail, it will'be understood that this is illustrative only and is not intended to be taken asa; definition of the scope of the invention, reference being had for this purpose to the appended claims. What is claimed is: I 1. In a torque transmission, a torque transmitting unit comprising a planetary difierential gear set, means inclosing the gears of ,saidgear set whereby they form a fluid plump, a tubular shaft extending axially through the gear set and formed with fluid inlet and outlet passages communicating with'the gear set, valve means in the shaft controlling the passages, the shaft being connected to one element of the gear set, a second shaft connected to another element of the gear set, and a one-way brake connected to. a,

third element of the gear set.

2. In a torque transmission, a, torque transmitting unit comprising a planetary differential gear set, means inclosing the gears of said gear set whereby they form a fluid plump, a tubular shaft extending axially through the gear set and formed with fluid inlet and outlet passages communicating with the gear set, a'valve sleeve slidable axially in the shaft having ports therein movable into register with the inlet and outlet passages to control the pumping action of the gear set, the shaft being connected to one element of the gear set, a second shaft connected to another element of the gear set, and a one-way brake connected to a third element of the gear set.

3.'In a torque transmission, a torque transmitting unit comprising a planetary gear set including a gear carrier, planet pinions on the gear carrier, and sun and ring gears meshing with the planet pinions, the gear carrier having side plates overlying and fitting against the ends of the pinions and gears, means between the side plates iitting against the ends of the gear teeth, one of the side plates being formed with inlet passages communicating with the gear teeth and there being outlet passages through the side plates communicating with the gear teeth, a housing inclosing the gear set into which fluid under pressure from the outlet passages discharges, the planet carrier having axially extendingopenings therethrough connecting the housing on opposite sides of the gear set to equalize the pressure therein. 1

4. In a torque transmission, a torque transmitting unit comprisin a planetary gear set inl eluding a gear carrier, planet pinions on the gear carrier, and sun and ring gears meshing with the planet pinions, the gear carrier having side plates overlying and fitting against the ends of the pinions and-gears, means between the side plates fitting against the ends of the gear teeth, one of the side plates being formed with inlet passages communicating with the gear teeth and there being outlet passages through the side plates communicating with the gear teeth, a housing inclosing the gear set into which fluid under pressure from the outlet passages discharges, driving and driven shafts connected to two elements of the gear set respectively, and a oneway brake connected the third element of the gear set. w

5. in atorque transmission, a gearunit com prising spaced parallel side plates, intermeshirlg v gears between the plates with their ends engaging and sealing against the plates, blocking means between the plates inclosing the outer edges of the gear teeth to form a gear pump, one of the plates being formed with an inlet passage communicating with the gears and there being outlet passages through the plates communicating. with the gears, and a casing inclosing the gear unit into which fluid under pressure from the outlet passages discharges so that fluid pressure in the casing will tend to hold the plates against the gears, at least one of the gears being supported between the plates on hollow mounting means extendingthrough the plates -to connect and equalize the pressure on opposite sides thereof.

6.,A torquetransmission comprising a pair of planetary differential gear units each having means inclosing its gears. whereby they form av iiuid pump and means forming inlet and outlet passages therefor, a driving shaft connected to one element of one gear unit, an intermediary shaft interconnecting a second element of said one unit and one element of the other unit, a driven shaft connected to a second element of said other unit, one-way brakes connected to third elements of each of said units, and valve means controlling the inlet and outlet passages to change the driving conditions of the units.

7. A torque transmission comprising a pair of planetary difierential gear units each having means inclosing its gears whereby they form a fluid pump and means forming inlet and outlet passages therefor, a driving shaft connected to one element of one gear unit, an intermediary shaft interconnecting a second element of said one unit and one element ofthe other unit, a driven shaft connected to a second element of said other unit, one-way brakes connected to driven shaft connected to a second element ,of

said other unit, one-way brakes connected to third elements of each of said units, said intermediary shaft being hollow and having ports therein communicating with said passages respectively, and a valve member slidable axially in the intermediary shaft to control the ports.

9. A torque transmission comprising a pair of planetary differential gear units each having means inclosing its gears whereby they form a fluid pump and means forming inlet and outlet passages therefor, a driving shaft connected to one element of one gear unit, an intermediary shaft interconnecting a second element of said one unit and one element of the other unit, a driven shaft connected to a second element of said other unit, one-way brakes connected to third elements of each of said units, said intermediary shaft being hollow and having ports therein communicating with said passages respectively, a tubular valve slwve slidable axially in the intermediary shaft and having ports thereto control .the passages, and means forming a co nection froma supply of operating fluid into the valve sleeve.

10. A transmission for connecting a driving shaft to a driven shaft comprising a torque transmitting unit so constructed and arranged that it'will transmit and interrupt torque flow, said unit having a driving membenconnected to the driving shaft and a driven'member, a pinrality of diiferential gear sets in series each having one element connected to the driven member of the preceding unit and another element connected to the driving member of the succeeding unit with said other element of the last gear set i the series connected to the driven'shaft, a one-way brake connected to a third element of each gear set, means inclosing the gears of each gear set whereby it forms a fluid pump, and valve means for selectively controlling the flow of fluid through the gear sets whereby they may be caused to act as reduction units or as fluid clutches.

11. A transmission for connecting a driving shaft to a driven shaft comprising a torque transmitting unit so constructed and arranged that it will transmit and interrupt torque flow, said unit having a driving member connected to the driving shaft and a driven member, a pair of planetary gear sets 'each having a sun gear, a ring gear, a planet carrier, and pinions on the carrier meshing with the sun and ring gears,

means cooperating with the carriers to inclooe the gears of the gear sets tq form fluid pumps,

said driven member being connected to the ring gear of one gear set, a one-way brake holding the sun gear of said'one gear set against reverse rotation, means connecting the carrier of said trolling the flow of fluid through the gear sets.

12. In a torque transmission, a torque transmitting unit comprising a planetary gear set including a gear carrier, planet pinions on the gear carrier, and sun and ring gears meshing with the planet pinions, the gear carrier having side plates overlying and fitting against the ends of the pinions and gears, means between the side plates fitting against the ends of the gear teeth, one of the side plates being formed with inlet passages communicating with the gear teeth and there being outlet passages thru the side plates communicating with the gear teeth, a housing enclosing the gear set into which fluid under pressure from the outlet passages discharges, the gear set and the housing being so constructed and arranged as to provide passages connecting the housing on opposite sides of the gear set to equalize the pressures therein.

ADIEL Y. DODGE. 

